There are many examples of medical devices having distal portions for inserting into subjects' bodies. For example, the distal portion of an endoscope is advanced into a body lumen (such as the gastrointestinal tract) in order to visualize and/or record an image from inside the lumen. A colonoscope is an endoscope, a distal portion of which is inserted into the colon for visualizing and/or recording an image of the colon.
PCT Publication WO 05/065044 to Cabiri et al., describes apparatus for use with a biologically compatible fluid pressure source. The apparatus includes an elongate carrier, adapted to be inserted through a proximal opening of a body lumen, and a piston head coupled to a distal portion of the carrier. The piston head is adapted to form a pressure seal with a wall of the lumen after the carrier has been inserted into the lumen, and to be advanced distally through the body lumen in response to pressure from the fluid pressure source. The apparatus is configured to facilitate distal advancement of the piston head by facilitating passage of fluid out of the lumen from a site within the lumen distal to the piston head. The apparatus additionally includes an optical system, coupled to the carrier in a vicinity of the distal portion, the optical system having distal and proximal ends.
U.S. Pat. No. 4,306,446 to Fukuda describes apparatus for estimating the locality of a leaking spot in a pipeline which conveys a fluid, the apparatus comprising: a pair of detectors located on the pipeline at positions spaced from each other by a certain distance and adapted to detect pressures and pressure gradients at the respective positions; and an operating unit adapted to calculate the locality of a leaking spot on the basis of the pressure gradients and mean pressures as obtained by memory-holding the pressures.
U.S. Pat. No. 5,660,198 to Maclaren, describes a control system for monitoring and regulating fluid pressure at a remote and/or potentially hazardous location along the length of a fluid flow conduit, without requiring a pressure sensor device at the remote site. The control system comprises a controller responsive to fluid pressure and flow rate readings taken at a convenient and/or safe location along the length of the flow conduit, to derive fluid pressure at the remote site. The controller provides a display of the derived pressure and/or operates a control valve at the safe site to regulate the pressure at the remote site.